CVE-2025-40022
In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Fix incorrect boolean values in af_alg_ctx Commit 1b34cbbf4f01 ("crypto: af_alg -…
Published Oct 24, 2025 · updated Oct 15, 2026
In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Fix incorrect boolean values in af_alg_ctx Commit 1b34cbbf4f01 ("crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg") changed some fields from bool to 1-bit bitfields of type u32. However, some assignments to these fields, specifically 'more' and 'merge', assign values greater than 1. These relied on C's implicit conversion to bool, such that zero becomes false and nonzero becomes true. With a 1-bit bitfields of type u32 instead, mod 2 of the value is taken instead, resulting in 0 being assigned in some cases when 1 was intended. Fix this by restoring the bool type.
Code
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Timeline
Detection, updates, and resolution for this record.
Oct 24, 2025 · NIST NVD
Detected
In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Fix incorrect boolean values in af_alg_ctx Commit 1b34cbbf4f01 ("crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg") changed some fields from bool to 1-bit bitfields of type u32. However, some assignments to these fields, specifically 'more' and 'merge', assign values greater than 1. These relied on C'
Oct 15, 2026 · NIST NVD
Updated
In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Fix incorrect boolean values in af_alg_ctx Commit 1b34cbbf4f01 ("crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg") changed some fields from bool to 1-bit bitfields of type u32. However, some assignments to these fields, specifically 'more' and 'merge', assign values greater than 1. These relied on C'
Sources
- CVE.orgVulnerability recordCVE-2025-40022
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2025-40022
30-day exploitation probability 0.2%
first.org - NIST NVDVulnerability recordCVE-2025-40022
In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Fix incorrect boolean values in af_alg_ctx Commit 1b34cbbf4f01 ("crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg") changed some fields from bool to 1-bit bitfields of type u32. H
nvd.nist.gov